In a computer system, a kernel is a program that comprises a central core of the computer's operating system. A shell (e.g., bash, csh, ksh, etc., in Unix-based operating systems) is a program and a component of the operating system that interacts with user commands. The shell therefore acts as an interface and a command interpreter for executing user commands. The commands can be programs or tools for performing simple tasks such as reporting a snapshot of the current processes (via the “ps” command) and ascertaining memory usage per process. Users can also combine a set of the shell commands to perform more complex tasks, create shell scripts and save the shell scripts for future use.